Abstract: A balcony assembly for attachment to a load-bearing structure of a building is provided. The assembly has a plate of low thermal mass composite material such as fiberglass. A supporting structure attached to the plate provides rigidity. An anchor is configured to attach one side of the balcony assembly to a floor of the building in a cantilevered arrangement. The balcony assembly is useful in minimizing heat transfer through concrete floor slabs, and has the added benefit of reducing the overall weight of the balcony, which in turn allows lighter construction of the building.